Printed matter



Patented Aug. 5, 1930 UNITED STATES 'APATENT'O'FFVICE ALBERT B. DEWEY,JR., 'AND'NICHOLAS I). CHERONIS, OF CHICAGO, ILLINOIS; SAID CHEBONISASSIGNOR TO SAID DEWEY rnm'rnn MAT'rER 1T0 Drawing.

Our invention relates to printed matter,

1 witha solution containing potassium ferri-' cyanide and ferricammonium citrate. Theaddition of a very small amount of a uranium saltsuch as uranium nitrate will mate rially accelerate the response of thefinished paper.

The finished and unexposed paper may receive indicia printed thereon inink prefer ably of a color substantially identical with the blue colorthe paper will hav'eafter exposure to light either with orwithoutsequent immersion in watch: 3

It may also receive another or alternative set-of indicia printed withink-of acolor substantially identical with the color of theundevelopedpaper, which, in case of the blue printpaper described above,will be a pale yellowish whitef Anys'uitable ink may be employed forthis purpose. We prefer 'a colloidal ink composed primarily of aquickdrying varnish capable of printing in a thin film, and a pigmentsuspended therein.

f. The paper thus prepared is placed in a lighttight envelope beforeexposure and may then be mailedor'otherwise transmitted to itsdestination. If the paper is folded with the sensitive face innermost,the folding will assist in protection against light. The en- "velepe.may.be made light-tight by a black I lining or by coloring the insideblack or some other protective color.

,When the recipient opens the envelope and gremoves the sheet of paper,if the paper car,-

aries any indicia in ink of the final color, he-

willbe confronted at once with the message @carried by that set ofindicia. As'the paper =5 'lies before him exposed to the light of the'sub- Application filed January 30, 1928. Serial No. 250,714.

room, the color of the paper background will change from the originaltoward the final color and the set of indicia printed in the originalcolor will become visible. Simultaneously, the set of indicia printed inthe final color will disappear.

Such a paper as that described after being allowed to remain in awelllighted place for five to ten minutes, may, if desired, be

immersed in water to fix and render the final coloration permanent. Ifthe pigment ink complete obliteration of the indicia after a few weeks.

'" In preparing the paper in the first instance,

= an additional design or set of indicia may be embodied in thesensitizing itself as follows: The paper is first treated with arelatively weak solutionand then dried' The desired design or set ofindicia may now be printed:

on the face of the dry paper using, for ex-' ample, a'volatile oil notsoluble in water. After this printing the paper is treated a second timewith a sensitizing solution. The a second solution may be largelyprevented from impregnating the areas, printed with the volatile oil. Indrying after the second treatment, a good circulation of air willevaporate the volatile oil.. This productmay then be printed withpigment inks as indicated above.

When this paper reaches its destination the results will be like thosein the instance already described, except that the design in the paperwill appear like a more or less conspicuous water-mark in the backgroundof the final golor.

Thus, aieircular might present the reader: with a brief message in blue,on an almost white background. By the time this message had been read,it would be'comepro gressively more or less obliterated, and a secondmessage in white on a blue background would progressively appear. As thesecond message becomes more and more distinct, the marking in thebackground will also become noticeable.

color at'v'ai'ious speeds, as by varying the content of uranium nitrate,the speed with which difierent portions of the paper sheet will respondto exposure may be varied. By

this means the speed with which the reader will peruse the message maybe controlled to concentrate attention on various portions of themessage, or merely to require thoroi-igh perusal ofall of it, or both,and this varying sensitivity may be employed either as a continuous or adiscontinuous step-by-step vari-. ation.

It is not essential that all the novel features of the invention beemployed in conjunction, as they may advantageously be utilized invarious combinations and sub-combinations.

What we claim is 1. Apiece of printed matter having an area covered withink, another area sensitive to light to develop a change of color at apredetermined speed and to a predetermined final tint, and a third areasensitive to light to develop a change of color at a predetermined speedand to a predetermined final tint, the speed and the final tint for thethird area being different from the speed and final tint for the secondarea, said first area over- 1 'ng' ortions of said second and thirdareas, t e in covering said first area being of fugitive color andbecoming transparent after prolonged exposure to light.

2. Apiece of printed matter having an area covered with ink, a secondarea sensitive to light to develop a change of color at a predeterminedspeed and to a predetermined final tint, and a third area sensitive tolight to develop a change of color at a predetermined speed and to apredetermined final tint, the speed and the final tint for the thirdarea bein different from the speed and final tint for t e'second area,said first area overlying lportions of said second and third areas.

3. piece of printed matter having an area covered with ink, a secondarea sensitive to light to develop a change of color at a predeterminedspeed and to a predeter mined final 'tint, and a third area covered withink, the color of said first area being substantially identical with theundeveloped color of the second area, and the color of said third areabeing substantially identical with the developed color of the secondarea.

4. A piece of printed matter having an .area covered with ink, a secondarea sensitive to light to develop a change of color, the covered areabeing substantially identical in color with the original unexposed colorof said second area.

5. A sheet of material having an area of permanent color, and a secondarea sensitive to light to develop a change .of color, the color of saidfirst area being substantially identical with the original unexposedcolor of said second area.

6. A piece of printed matter having an area covered with ink, a secondarea sensitive to light to develop a change of color at a predeterminedspeed and to a predetermined final tint, and a third area sensitive tolight to develop a change of color at another predetermined speed and tothe same predeternu'ned final tint.

7. A sheet of material having an area of permanent color, a second areasensitive to light to develop a change of color. and a third area ofpermanent color, said second area being substantially identical in colorwith said first area before exposure and with said third area afterexposure.

8. A piece of printed matter having an area of permanent colo r, asecond area sensi tive to light to develop a change of color to saidfirst area being substantially identical with the initial unexposedcolor of said second and third areas.

9. A piece of printed matter comprising a sheet impregnated withchemicals was to change color upon exposure to light, and indiciaprinted on said sheet in 'pigmentink of a color identical with'the oriinal color of the sheet, diflerent portions of said sheet havingdifferent sensitivities so as to develop at different speeds said sheetbein susceptible of intensification and fixing 0 its color by immersionin water.

10. Apiece of printed matter comprising a sheet impregnated withchemicals so as to change color upon exposure to light, and indiciaprinted on said sheet irilpigmeritink of a color identical with theoriginal color of the sheet, said sheet being susceptible ofintensification and fixing of its color by immersion in water.

11. A piece of printed matter comprising a sheet impregnated withchemicals so as to change color upon exposure to light, and i11 diciaprinted on said sheet in pigment ink of a color identical with theoriginal color of the sheet.

12. A piece of printed matter'comprising a sheet impregnated withchemicals so as to change color upon exposure to light, and indiciaprinted on said sheet in pigment ink of a color identical with one ofthecolors taken by the sheet itself during exposure.

13. A piece of printed matter comprising a sheet impregnated withchemicals so as to face to change color upon exposure to 1i ht andbearin' indicia of a permanent co or similar to t eoriginal color ofsaid surface and also bearing lndicia of a color difierent from saidoriginal color.

16. A sheet having a light-sensitive surface to change color uponexposure to light and having indicia printed on said surface in ink of acolor not contrasting with the original. color of said surface-but whichwill contrast with the final color thereof.

17. A sheet having a light-sensitive surface to change color uponexposure to light and having indicia printed on said surface in ink of acolor not contrasting with the original color of said surface but whichwill contrast with the final color thereof,' and also having printed onsaid surface indicia inlink of a 'color difierent from the original coor.

In testimony whereof, I have signed my ecification.

LBERT B. DEWEY, JR. In testimony whereof, I have signed my name to thisspecification.

NICHOLAS n. orninoms.

name to this s

